Methods of forming aluminum oxide layers on substrates are disclosed. In some embodiments, the method includes depositing an aluminum oxide seed layer on the substrate using a first process having a first deposition rate. The method further includes depositing a bulk aluminum oxide layer atop the seed layer using a metalorganic chemical vapor deposition (MOCVD) process having a second deposition rate greater than the first deposition rate.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of forming an aluminum oxide layer on a substrate, comprising: depositing an aluminum oxide seed layer on a substrate using a first process having a first deposition rate; and depositing a bulk aluminum oxide layer atop the seed layer using a metalorganic chemical vapor deposition (MOCVD) process having a second deposition rate greater than the first deposition rate.
2. The method of claim 1 , wherein the MOCVD process further comprises: flowing a metalorganic precursor and an oxygen-containing gas into a process chamber having the substrate contained therein; and forming the bulk layer on the substrate from aluminum, provided by the metalorganic precursor, and the oxygen-containing gas.
3. The method of claim 2 , wherein the MOCVD process further comprises: flowing nitrogen (N 2 ) along with the metalorganic precursor.
4. The method of claim 2 , wherein the metalorganic precursor is at least one of triethyl(tri-sec-butoxy)dialuminum (EBDA), trimethyl aluminum (TMA), or tetrakis[diethylamino]aluminum (TDEAA, Al[N(C 2 H 5 ) 2 ] 4 ).
5. The method of claim 2 , wherein the oxygen-containing gas is oxygen (O 2 ).
6. The method of claim 2 , wherein the seed layer is deposited to a thickness of between about 3 to about 20 Angstroms.
7. The method of claim 2 , wherein the bulk layer is deposited to a thickness of between about 100 to about 200 Angstroms.
8. The method of claim 2 , wherein the seed layer is deposited by at least one of an atomic layer deposition (ALD) process, a pulsed chemical vapor deposition (pulsed CVD) process, or a metalorganic chemical vapor deposition (MOCVD) process.
9. The method of claim 8 , wherein depositing the seed layer further comprises: pulsing an aluminum-containing gas and an oxygen-containing gas; and maintaining the substrate at a first temperature; wherein depositing the bulk layer further comprises: flowing a second process gas at a second flow rate; and maintaining the substrate at a second temperature, wherein the first temperature is less than the second temperature.
10. The method of claim 9 , wherein depositing the seed layer further comprises: purging the aluminum-containing gas and the oxygen-containing gas, wherein the pulsing and purging of the aluminum-containing gas and the oxygen-containing gas comprise a cycle.
11. The method of claim 10 , wherein the pulsing and purging of the aluminum-containing gas and the oxygen-containing gas is repeated for about 2 to about 5 cycles.
12. The method of claim 10 , wherein the pulsing or the purging has a duration between about 1 to about 10 seconds between gases.
13. The method of claim 10 , wherein a gas utilized for the pulsing and the purging comprises nitrogen (N 2 ).
14. The method of claim 13 , wherein the nitrogen has a flow rate of between about 7 to about 14 liters/minute.
15. The method of claim 10 , wherein the aluminum-containing gas has a flow rate of up to about 50 milligrams/minute.
16. The method of claim 10 , wherein the oxygen-containing gas has a flow rate of up to about 7 liters/minute.
17. The method of claim 1 , wherein the substrate comprises silicon and oxygen.
18. The method of claim 1 , further comprising: depositing the seed layer by flowing a first process gas comprising a metalorganic precursor and an oxygen-containing gas, wherein the metalorganic precursor includes aluminum and is provided at a first flow rate, and maintaining the substrate at a first temperature; and depositing the bulk layer by flowing a second process gas comprising a second metalorganic precursor and a second oxygen-containing gas, wherein the second metalorganic precursor is provided at a second flow rate, and maintaining the substrate at a second temperature; wherein at least one of the first flow rate or the first temperature is less than at least one of the second flow rate or the second temperature.
19. The method of claim 18 , wherein the second process gas further comprises nitrogen (N 2 ) provided at a flow rate of about 2 to about 7 liters/minute.
20. The method of claim 18 , wherein depositing the seed layer further comprises: providing the metalorganic precursor at a flow rate of about 1 to about 10 milligrams/minute.
21. The method of claim 18 , wherein depositing the seed layer further comprises: providing the oxygen-containing gas at a flow rate of between about 2 to about 7 liters/minute.
22. The method of claim 18 , wherein the second temperature is between about 500 to about 800 degrees Celsius.
23. The method of claim 1 , further comprising: annealing the deposited aluminum oxide layer in a process gas comprising at least one of hydrogen (H 2 ) and oxygen (O 2 ).
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 3, 2008
April 24, 2012
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